Certain conventional electronic devices are commercially available for monitoring intensive properties of NMR samples, such as an electronic pH meter that measures pH values for NMR samples by installing a sensor at the tip of a long, small-diameter rod and positioning such sensor inside an NMR tube, e.g., a 5 mm NMR tube. However, such a conventional device and technique requires the removal of the NMR tube from the NMR probe in order to measure the pH value of the sample. Removing an NMR tube for this purpose is inconvenient when monitoring chemical reactions by in situ NMR spectroscopy, especially when the pH changes unexpectedly and rapidly throughout the course of the reaction. Further, other conventional devices for monitoring NMR samples, such as an NMR temperature probe require placing the device in the probe, making a series of NMR measurements at different probe temperature settings, making a series of corresponding probe temperature measurements with an independent thermocouple or other electronic temperature sensor, removing the device from the probe, and creating a calibration curve. The NMR sample to be analyzed is then placed in the probe, the probe temperature setting is adjusted to a desired value, the NMR sample is allowed to equilibrate to the probe temperature, and the calibration curve is used to predict the temperature of the NMR sample. The explicit assumption is that the calibration curve provides an accurate prediction of the temperature of the NMR sample. It is often the case that the assumption is invalid and that the predicted temperature of the NMR sample is erroneous. Additionally, the conventional device is costly and the procedure for measuring and assigning the temperature of the NMR sample is extensive, tedious, time-consuming, and inherently prone to operator error. Furthermore, the numerical value of temperature that is assigned to the corresponding recorded NMR spectrum lacks incipient integrity and, therefore, can be called into question in legal proceedings.